Collapsible fuel tank



y 1950 M. M. CUNNINGHAM ETAL 2,508,906

COLLAPSIBLE FUEL TANK 4 Shee ts-Sheet 1 Filed Jan. 16, 1945 ATTORNEY May 23, 1950 M. M. CUNNINGHAM EI'AL COLLAPSIBLE FUEL TANK 4 Sheets-Sheet 2 Filed Jan. 16, 1945 w HR. It m 31% m k Mum ATTORNEY y 3, 1950 M. M. CUNNINGHAM ETAL 2,503,906

COLLAPSIBLE FUEL TANK 4 Sheets-Sheet 3 Filed Jan. 16, 1945 Ml V1 m m T/VW W m WW6 T. WW .1 C oi A M Ma M. M. CUNNINGHAM ETAL 2,508,906

COLLAPSIBLE FUEL TANK 4 Sheets-Sheet 4 May 23, 1950 Filed Jan. 16, 1945 ATTORNEY ternally of rthe cel-l.

Patented May 23, 1950 COLLAPSIBLE FUEU TANK :MarionqMrCu-nningham andGeorge P. McDowell;

.South. Bend,.Ind., assignorsto United .States Rubber .Company, New York, N.' Y a .corpora- .tion of NewiJersey Application ilanuary 16,'1945,;1Serial No. 573,128 1 .10.. Claims. (o1..244-1s5) iburjinventionrelates-:to: liquid containers and :more particularly: to improvements ,incollapsible *fuel tanks orzcells.

" In the-manufacture and .useof liquid con- -'=tainers,.suchas the-fabricated fuel. cells used :as airplanetanks, fdiii'icul-tyz-isv encountered in 'manufacturing' the seams where the" edges :of

ithe coated zfabri'c' are brought together. Ananther problem: involved: at. thetseams is the nes-cessityfi for" keeping the edges of: the fabric away i'froma the. ccntentstof thecell-t and 1305 rely on the fabric coating for preventing capillary-attraction 101*: seepagethroughthe. fabricso that the exterior :iof the-'cell'remains' free-from the cell. contents.

This particularly important -when the cells are? used: for transporting. inflammable: materials -:*such as; gasoline.

We overcome some? of; the: foregoing difiiculties :by reducing the number of seams.- andproviding a-seam constructiorrin whichithe-edges of the *fabric and-coatingat the. seams extend r ex- The seams are. reinforced both internally andexternally without materially impairing the. collapsible characteristics act-the cell.

Another. difiiculty encountered in the opera- "tien; of. such fuel: cells, is thev manner of attachment-of the: .-cells to the-supporting structures, .:such: as airplane frames.

e have -.provi-ded a -.quichly attachable. and

detachable. means forsecuring such cells. to the vead'j acent structuralrelements.bythe.manipulation of "hand-lesion knobs extending inwardly-of the :cells. -.The handles. o1 knobs 'ma'y bev reached through the 1101 1113112 service. opening; .if the cell .he:small, or by- .an operatorpositioned within :the. cell,; it the cell be: large.

The accompanying drawings-illustrate certain present. preferred: :forms .of. the invention in which:

Fig.1], is. an explodedview of .the shapes of. the several. coated..- fabric v elements before .they are ebmughttogether;

Fig. 2 is a perspectiveyiewof thecelL partially .brokenawam. looking, from the'..bottom;.

. "Fi .3. is..-a. perspective view,..looking ;down.on .thec'ell';

Fig. 4..is a view,.similar toFig. 1, of amo'difica- 'tion oi the'jinvention;

-Fig.. 5. is .a cross-sectional view .of the cell .;mounted within. a supporting structure of an a.irp1ane, thex.celli.b.eing. out along. sectionjline of Ii'i'gr 3 :Fig... 6;. is @a. transverse sectional..,view through the wing. structuretakenon lineIVI Vlof.Fig.;5;

Fig; 7 is anenlarged detail viewinsectionillustrating in. detail... one. of. the. seams ,Fig. 8. is. acorner. view oiLthev cell;

Fig. 9. is. .a. GIOSSrSGQtiOHaI enlargementof one of. the fastening, elements ,takenalong .thesection line IX-.IX.. of.Fig...5;

Fig. 10 is a cross-sectional view .of .another .fasteningelement taken along the. section line .X-Xof-Fig. 6;

I Fig. .11 is. aadetail. view ,ofta .;portion.- of .the fasteningrelement. shown in.Flg. 1.0;.

Fig. 12 is a persepctive-yiew of. a cell broken away-Jo show .areinforcing. frame, in the bottom; I

,.F ig...13 is a perspectiueview ofv .the .frame. re-

- moved. fromthe. cell;

. Fig. 14. is a.detail..-of.a connectiomplughforuthe frame sections; and

Fig...15...is a ,cross..-sec.tion ,of the frame .and

attaching. means taken .on. theJine. XV.XV..Of

.Fig. .12.

Referringparticularly to. Figs..l to. 3,. and Figs.

.7 and 8,. alliquid container or cellembodying our invention comprises. v.a plurality. of .strips .of coated. fabric l..-an.cl..2. The strip I is folded transversely to providefounsurfaces of the. cell,

andthe-endseoi the edges. 3 .and .4 ,are .united .bya seam 5. Thestripsj.are-unitedftostrip l by seams 6 and].

As..-is..particularl-y shownin Fig. f7,.the.f.abric strips.eachicomprisesa layerof fabric 8 ,Which is-coatedat least on..its .inner surface with a .layerof plastic composition .9 which sealsthe fabric. and is resistant to. the .contents of .the cell. Thefabricfi. is. preferably a, square woven fabric and, the coating. composition 9 may be of synthetic rubber ornatural. rubber having .a .fiurther, coating ll l of .a material resistant .to .thecell contents. Variations. in the fabric and .thecoating may bemade as desired.

The seams 6 .are formed exteriorly .of the .main bodyof thecell by. having the. .faces of the contiguous. coatings .9 and I!) extend outwardlyof thecell in engagement with each other at the cell corner. These surfacesmay be treated yvitha bonding adhesive, tocause adhesion; when .the cellis cured, or they maybe vulcanized .directly. .together. .Reinforcing stitching ,l'l ;is passed through the seams externally of the cell.

For adding stabilityto the cell and for plosing anyseam 6,.a flange or angle piece ll ,of natural rubber or synthetic. rubber, depending on the nature of the cell contents, is placed within the cell behind the seam li and permais mounted.

3 nently secured to the coating layer l durin the cell curing or vulcanizing step.

In the manufacture of the cell, a destructible form is provided about which the strips I and 2 are shaped. Before shaping the strips l and 2, the angle pieces (2 are placed on the form at the corners thereof so that they are in position when the seams are completed. The seams and 1 are of a similar construction.

Referring to Fig. 8, provision is made at some corners of the cell for admitting a sewing machine or a trimming machine by terminating the seam flanges beforev they meet and reinforcing the cell corner with a. pad or cover I4. In

this construction the seamed edges may be read ily trimmed and sewed.

Our cell eliminates much of the labor and care heretofore involved in making lapped seams where auxiliary sealing means had to be applied over the edges of the fabric to prevent capillary attraction and in addition the seams of the present invention are stronger and more reliable.

The seam flanges add a certain amount of staseams necessary to join the top edges of the strips 2 of Fig. l to the strips I.

On mounting such containers in their supporting structures they are frequently placed inside a metal container or casing l5 which is previously inserted in a, cavity in a structural frame work I 6 of the machine in which the cell In the drawings, the structural frame work it is illustrated as a portion Of the wing surface of an airplane and comprises a lower wing surface l1, a lower bracing section IS, an upper bracing section 19 and an upper wing surface 2!). It is to be understood that the structure IE may provide a plurality of cavities in which the casings l5, usually of different sizes and shapes, may be inserted.

For placing the cell in the casing 15 a section 2 2! of the bracing structure 13 is made removable to provide an opening which is ultimately covered by the metal of the wing surface l1.

Above the removable section 2|, the casing I5 is provided with a removable plate 22 which is secured to the remainder of the casing by screws 23, threaded in plates 24. The cell is provided with a service or manhole plate 25 which is seworking through the opening can reach substantially all parts of the interior of the cell.

. In the case of large cells the plate 25 and the fitting 26 may be made large enough to permit the operator to enter the cell.

. The cell is also provided with one or more fittings 21 for the attachmentof an outlet pipe, not shown, and a fitting 28 for the attachment of a vent, not shown.

For securing the cell walls to the frame work 4 l6, we have provided quickly attachable and detachable securing means which can be manipulated from the interior of the cell either by an operator reaching through the opening in the fitting 26 or by entering the cell, as may be necessary. In either case, the operator can manipulate the fastening means from the interior of the cell into a cooperative engagement with complementary securing means attached to the frame ring 36 extend outwardly of the cell.

several of the fastening means 3| are disposed about the upper surface of the cell and each includes a handle 29 extending into the cell. Each handle 29 is provided with a pin 32 having a neck 33 and button 34. The neck 33 extends through a plate 35 from which spring fingers or a, split A male button 31 is secured radially inwardly of the fingers 35 to provide a channel38 for a wire C-ring 39. A covering 40 of a suitable plastic material such as synthetic rubber encases the outer part of the pin 32 and provides the gripping surface of the handle 29. The covering 40 is bonded to the pin 32 and the lower face of the plate 35. The coating 40 extends radially outwardly as a tapered disc or flange 4| which also overlaps a portion of the upper face of the plate 35 and terminates a distance from the split fingers 35 to permit the latter to have flexing movement. However, the coating 40 and the flange 4i seal the fastener fingers from the contents of the cell. The fabric 8 and the coating composition 9 are attached to the flange 4|, but termiof the handles 29 and the attached fingers 36 and button 31 there is provided an openings 42 in the casing l5. A plate '43 having a depending female spring button 44 internally carrying 0- ring 39 is positioned over each opening 42 and a cap piece 45 is placed over each plate 43, and secured in position by rivets 46. The plate 43 is of less diameter than the inner diameter of the cap piece 45 so that the plate 43 is capable of considerable lateral adjustment in the opening 42 to permit limited. adjustment of the position of the button 44. The button 44 is aligned to pass between the fingers 36 and the button 31 and to snap the ring 39 behind the head of the spring button 31. The construction just described provides a snap button construction by which the handle 29 may be quickly secured to the plate 43, or detached therefrom by an operator working from within the cell.

Referring to Figs. 5, 6, 10, and 11, each handle 3!] comprises a pin 50 having an outer button 5|, a neck 52, a flange 53, and a recess 54 for the reception of a plate 55. The flange 53 and the plate 55, as well as the inwardly extending end of the pin 50, are covered by and bonded to a coating composition, such as synthetic rubber, terminating in a tapering flange to which the fabric 8 is attached in the manner set forth in the description of Fig. 9. The button 5! is adapted to sit in a bayonet slot 56 formed in the casing smas es position. The'spiing -T-'is 'proifidedwiii'th a-tl'etent ""fifl for engaging a 'recess 59-at the end "of -the pm .c'icellawall-and 2the2spring-ii5z1 .-In.. order":to release the fastening means, the handle SBEL-EiSLIIa-iSEd against -.the ifrictiontxof -the springcliil until the flange .5l can be withdrawn through the enlarged portion of the opening 56. Tf-necessary,*openings If-58" may betiprovided iniad'j acent' portionsof' -the iiaiiiplane structure to provide clearance for =-"the :"springs .51.

In some 'ce'll' "structures, irregularities "in "the shape of the plane wings or cells of large sizes render it advisable to use a bracing device at the bottom of the cells in order to prevent shifting of portions of the cell walls relative to the plane structure, whereby the cell is normally held in extended position to substantially conform to the size of the Opening in the plane.

In Figs. 12 to 15 we have shown such construction in which a frame 66 preferably comprising perforated pipe sections 6!, 62, 63, and 64 are joined together by rubber plugs 65, 66, 61, and 68 which are inserted in the adjacent ends with the pipe sections. The frame is held in position by tabs 69 which are bonded to the corner strips l2 and the cell corners l3. Tapes 10 are secured to the tabs 69 as by stitching H to provide free ends which can be brought over the pipe sections and. tied as shown at 12 in Figs. 12 and 15.

The perforations 13 in the pipe sections permit the cell contents to flll and escape therefrom so that the capacity of the cell is not materially reduced and there is no buoyant effect produced by the pipe sections.

In assembling the frame 66 in the cell the sections :are first bent at either of the plugs 65, 61 or 66, 68, depending upon the size and shape of the cell, and then the collapsed frame inserted through the manhole. The frame 60 is next tied in the bottom of the cell, as illustrated in Figs. 12 and 15.

This construction has a further advantage in that it does not restrain the lower part of the tank with respect to the airplane structure so that a considerable amount of deformation of the cell may take place in a crash.

It will thus be seen that we have provided improvements in the construction of seams of such cells and in the means for fastening the cells to the supporting structure.

While we have shown and described certain preferred embodiments of our invention, it is to be understood that the invention may be otherwise modified within the spirit of the invention and the scope of the appended claims.

Having thus described our invention, what we claim and desire to protect by Letters Patent is:

1. A cell comprising a flexible wall and means for securing the wall to a supporting structure comprising an attaching element forming a unit with and extending outwardly of the cell, and manipulating means for the element extending inwardly of and secured to the cell for attaching and detaching said element from an individual mating element on the supporting structure.

2. A cell comprising a flexible wall and means for securing the wall to a supporting structure mom-prising a button' formmga unitawith-andiaextending' oiitvvardlysof the cell, and vmanipnlating means for the button extending inwardly Ofi'sflill'd "secured --to the cell for attaching :and detaching saidbutton from ra corresponding individual ma ting element on the supportingwstrncture.

" 3. A cell comprising a fiexibleewallrandrmeans "for securin the wall =to ansupportings structure comprising a snap button forming 1a unit .KiWllFh and extending outwardly of the cell-, and-:manipule-ting means for the snap button extending; inwardly of and securedtto" the cell forzattaching -==and* detaching said button from a complemen- *tary button on the supporting structure.

" an inner coatingcomposition *therefor "resistant -ingthe walls to' a supporting structurecomprising buttons extending outwardly or the :cell

through openings in the fabric, and manipulating means for the buttons extending inwardly of and secured to the cell and sealing the edges of the fabric at said openings from the cell contents.

5. A cell comprising a flexible wall and quickly operative means for securing the wall to a supporting structure comprising attaching elements forming a unit with and extending outwardly of the cell and a handle in alignment with each element extending inwardly of the cell for the separate actuation of the aligned element.

6. The combination with a supporting structure having fixed supporting elements, of a flexible cell provided with an entrance opening and having formed as a unitary part thereof outwardly extending supporting elements for cooperation with the elements on the structure and manipulating means secured to and extending inwardly of the cell in alignment with the element on the cell, whereby an operator working through said entrance in the cell may selectively manipulate the elements on the cell into engagement with the elements on the structure.

7. The combination with a supporting structure having fixed supporting elements of a quickly attachable character, of a flexible cell provided with an entrance opening and having outwardly extending supporting elements of a quickly attachable character for cooperation with the elements on the structure, and manipulating means extending inwardly of and secured to the cell in alignment with the elements on the cell. whereby an operator working through said entrance in the cell may selectively manipulate the elements on the cell into engagement with the elements on the structure.

8. The combination with a cell enclosing structure having normally horizontal and vertical surfaces for enclosin a cell and fixed overhanging cell supporting elements and fixed laterally extending cell supporting elements fixed to said structure, both of which elements are of a quickly attachable character, of a cell composed of coated fabric having an entrance opening therein, laterally extending attaching elements and upwardly extending attaching elements extending from said cell for cooperation with the elements on the structure, and handles extending inwardly of the cell and attached thereto in alignment with the outwardly extending elements, whereby an operator working the handles through the opening in the cell may separately actuate the elements on the cell into engagement with the elements on the structure.

9. A cell comprisin a flexible wall, a, supporting structure for said wall having an opening therein provided with an enlarged portion and a narrower extremity, an attaching head aflixed to said flexible wall, said head being smaller than said enlarged portion but larger than said narrower extremity of said opening, a groove at the base of said head adapted to receive the edges of the narrower extremity of said opening, and manipulating means for said head extending inwardly of said cell and secured to said wall.

10. A cell comprising a flexible wall, a supporting structure for said wall having an opening therein provided with an enlarged portion and a narrower extremity, an attaching head fixed to said flexible wall, said head being smaller than said enlarged portion but larger than said narrower extremity of said opening, a groove at the base of said head adapted to receive the edges of the narrower extremity of said opening, manipulating means for said head extending inwardly of said cell and secured to said wall, and a spring attached to said supporting structure and adaptedto act on said head to hold same in said narrower extremity.

MARION M. CUNNINGHAM.

GEORGE P. McDOWELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS manner Date Name 15 1,297,305 Thacher Mar. 11, 1919 2,102,590 Gray et a1. Dec. 21, 1937 2522,104 Arcier June 15, 1943 2,395,606 Zlnkil Feb. 6, 1946 

